Known in the art is a process for preparing propylene oxide and acetic acid the oxidation of propylene and acetaldehyde with an oxygen-containing gas in a liquid phase in the presence of a homogeneous catalyst at a temperature within the range of from 150 to 250.degree. C. As the homogeneous catalyst, use is made of salts of cobalt, manganese, ruthenium. Selectivity of the formation of propylene oxide as calculated for the reacted acetaldehyde is 35 molar percent.
This prior art process has a disadvantage because of a low selectivity of the formation of propylene oxide as calculated for the reacted acetaldehyde.
Known in the art is also a process for preparing propylene oxide and acetic acid the oxidation of propylene and acetaldehyde with an oxygen-containing gas in the presence of a heterogeneous catalyst such as silver oxide at a temperature of from 70 to 150.degree. C. under a pressure of from 2 to 60 atm. Selectivity of the formation of propylene oxide as calculated for the reacted acetaldehyde does not exceed 70 molar percent (cf. USSR Inventor's Certificate No. 334825). This prior art process is objectionable because there is an insufficient selectivity of the formation of propylene oxide as calculated for the reacted acetaldehyde.